Citation: Patent number: 6480615 Issue date: Nov 12, 2002
Abstract: The optical flow of an array of pixels in an image field is determined using adaptive spatial and temporal gradients. Artifacts are avoided for image objects which are moving smoothly relative to the image field background. Data from three image frames are used to determine optical flow. A parameter is defined and determined frame by frame which is used to determine whether to consider the data looking forward from frame k to k1 or the data looking backward from frame k1 to frame k in initializing spatial and or temporal gradients for frame k. The parameter identifies signifies the areas of occlusion, so that the gradients looking backward from frame k1 to frame k can be used for the occluded pixel regions. The gradients looking forward are used in the other areas.